A coil is configured with stacked n turns (where n is an integer of 2 or more) of spirally wound conductive wire having a rectangular cross-section. A k-th turn (where k is an integer and 1≤k≤n) of the coil has at least a straight portion and a corner portion extending from an end part of the straight portion. On an outer peripheral surface of the corner portion, there are formed at least a first bent portion bent toward an inner peripheral side and a second bent portion bent toward the outer peripheral side, and curvature C1 of the first bent portion is different from curvature C2 of second bent portion.